From b5ed54e94d324f17c97852296d61a143f01b227a Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Mon, 15 Nov 2010 06:38:13 +0000 Subject: bridge: fix RCU races with bridge port The macro br_port_exists() is not enough protection when only RCU is being used. There is a tiny race where other CPU has cleared port handler hook, but is bridge port flag might still be set. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/br_private.h | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'net/bridge/br_private.h') diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index b862071bf601..46e0bec1d7c5 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -151,11 +151,19 @@ struct net_bridge_port #endif }; -#define br_port_get_rcu(dev) \ - ((struct net_bridge_port *) rcu_dereference(dev->rx_handler_data)) -#define br_port_get(dev) ((struct net_bridge_port *) dev->rx_handler_data) #define br_port_exists(dev) (dev->priv_flags & IFF_BRIDGE_PORT) +static inline struct net_bridge_port *br_port_get_rcu(const struct net_device *dev) +{ + struct net_bridge_port *port = rcu_dereference(dev->rx_handler_data); + return br_port_exists(dev) ? port : NULL; +} + +static inline struct net_bridge_port *br_port_get(struct net_device *dev) +{ + return br_port_exists(dev) ? dev->rx_handler_data : NULL; +} + struct br_cpu_netstats { u64 rx_packets; u64 rx_bytes; -- cgit v1.2.3